Avaliação da atividade estrogênica em efluente sanitário bruto e tratado em uma estação de tratamento com sistema de lodos ativados com aeração prolongada

Abstract

Endocrine disruptors are compounds capable of causing harmful effects on health and can affect the growth, development, reproduction and behavior of living beings. These compounds are present in domestic effluents, mostly in the form of estrogenic compounds. Conventional treatment of domestic effluents does not objectively remove such substances, and consequently they affect water bodies. Therefore, the objective of this work was to determine the estrogenic activity of raw and treated sanitary effluent from a sewage treatment plant (STP) with a sludge system activated by prolonged aeration. The sanitary effluent was characterized from May 2019 to June 2022, in terms of physical-chemical parameters in relation to the physicochemical parameters and the estrogenic activity of the liquid phase by the in vitro assay, reported in nanograms equivalent of 17β-estradiol (ngEQ-E2. L-1). The STP achieved COD, TSS and N-NH3 removal efficiencies of 85%, 71% and 46%, in order. The STP managed to meet the standards of COPAM-CERH Resolution nº 8/2022, with the exception of N-NH3, which exceeded the maximum value allowed in 57% of collections. 85% of the raw effluent samples had estrogenic activity, while 50% of the treated effluent. Estrogenic activity in raw effluent varies between <LD and 543.90 ng-EQ-E2.L-1 and in treated effluent between <LD and 95.48 ng-EQ-E2.L-1, showing significant deviation between samples. The median EC50 was 84.11 ± 172.29 ng.L-1 and the LD and LQ were 0.15 ± 0.05 and 0.44 ± 0.14 ngEQ-E2.L-1, respectively. The recovery of the E2-doped sample was approximately 84%. The average estrogenicity removal was 86%, consistent with what is expected for LA systems and their variants. However, the estimated estimates in the receiving body after the discharge of the treated effluent were between 0.0005 and 0.43 ngEQ-E2.L-1. The maximum concentration is above values considered to potentially cause adverse effects on aquatic biodiversity. Therefore, it is concluded that it is necessary to adopt strategies such as the rational use of estrogenic compounds to minimize their concentrations in sewage, as well as to carry out more research that contributes to their inclusion as wastewater monitoring parameters, with the aim of encourage the adoption of strategies and new technologies that aim to increase their removal in STPs.